Arsenical compound.



' UNTTED STATES PATEN T G WALTER A. JACOBS, 01E MOUNT VERNON, AND WADE H. BROWN, MICHAEL HEIDEL- BERG-ER, AND LOUISE PEARCE, OF NEW YORK, N. 'Y., ASSIGNORS TO THE ROCKE- FELLER INSTITUTE FOR MEDICAL RESEARCH, OF NEW YORK, N. Y., A CORPORA- TION OF NEW YORK.

ARSENICAL COMPOUND.

No Drawing.

To all whom it may concern: Be it known thatwe, WALTER A. JACOBS, Ph. 1)., residing at Mount Vernon, Westchester county, New York, WADE H. BROWN 5 M. 1)., residing at Flushing, in the city 0% New York, borough of Queens, Queens county, New York, MICHAEL HEIDELEERGER, Ph.D., residing in the city of New York, borough of Manhattan, county and State of New York, and LOUISE PEARCE, M.'D., re-

siding in the city of New York, borough of Manhattan, county and State of New York, all citizens of the United States, have jointly invented a new and Improved Arsenical Compound, of which the following is a specification.

In the course of our researches and tests onthe' new type of arsenical compounds of use in the treatment of trypanosomal or $0 spirochmtal infections which we describe in our co-pending applications, Serial Nos. 194459 and 194461, and which are composed of'an aromatic arsonic acid possessing an oz-amino-acylamin side chain having the general formula NH.CHR.CQNR'R", in which B may be alkyl or aryl or hydrogen, and B and B may be alkyl or aryl or hydrogen, the aromatic nucleus being joined to the a-amino group in said side chain, we have so found that in certain instances, particularly in the treatment of spirochaetal infections, improvement in therapeutic power was obtained when the amid or CONT-I group was changed to the ureid or CONHCONH,

group or substituted ureid CONHCONPLR group, in which R may be an alkyl or aryl.

These substances were obtained by reacting the aminophenylarsonic acid or its homologues or isomers with a-halogenacyl' co ureas or a-halogenacyl-fi-alkylureas, or whalogenacyl-(i-arylureas. alkyl meaning methyl, ethyl, and the like, aryl meaning phenyl, substituted phenyl, benzyl or substituted benzyl and the like. As these sub- 415 stances are arsonic acids they dissolve readily in equivalent amounts of alkali or alkali carbonates or ammonia to form neutral and stable salts.

In particular our researches have demonstrated the value of the two substances des- Speeifioation of Letters Patent.

Patented se t. 2a, was.

Application filed October 3, 1917. Serial No. 194,460.

igna-ted as N-phenylglycin-ureid-p-a-rsonic ac1d with the following formula:

H cmcoNHcoNH,

Y to

HCH,CONHCONHCH;

These substances and the others to be described below represent a new type of arsenical compounds. The method of preparation is described as follows:

Emamplejs- N-Pitengigby cinweid p-arsenic 217 grams of p-aminophenylarsonic acid dissolved in one liter of normal sodium hydroxid solution or in an aqueous solution or suspension of any other suitable basic substance are mixed with gm. chloroacetylurea and the mixture boiled for oneas quarter of'an hour, after which a heavy crop of the crystalline product separates. The'mixture is then heated for three-quarters of an hour on the water bath. After cooling, the mixture is treated with hydrochlor1c acid until the reaction is distinctly acid to Kongo red. The mixture is then filtered ofi' and the residue washed well ill? with water. For purification the product is ill) All

(All

a-rsonic acid in pure form as microscopic needles. This is filtered, washed and dried. This arsonic: acid is almost insoluble in Water but is readily soluble in alkali and alkali carbonates. Its solutions give a precipitate with the heavy metal salts. Boiling acids and alkalis hydrolyze it to phenylglycinarsonic acid. It darkens above 230 C. but does not melt below 280 C. It forms stable salts.

The sodium salt is prepared in the following manner:

The acid is suspended in a small volume of warm water and carefully treated with 25per cent. sodium hydroxid solution until solution is just complete. It is advisable to make the solution neutral to litmus. An equal volume of saturated aqueous sodium acetate is then added, causing the separation of the crystalline sodium salt. This is filtered ofi' and purified by recrystallization, from a small volume of hot water. The salt thus obtained contains 2 molecules of water of crystallization and dissolves readily-in water.

Example ll.--N Phenylglg oin -15 methylurez'd-p-msom'c acid.

217 grams p-aminophenylarsonic acid are dissolved in one liter of normal sodium hydroxid solution. 155 gm. a-chloroacetyl- B-methylurea are added and the mixture boiled for one hour. The chloro compound gradually dissolves and during the reaction, the reaction product suddenly crystallizes out.

After cooling, the mixture is treated with an excess of concentrated hydrochloric acid and filtered. The product, after washing, is purified as in Example I.

The N phenylglycin-fi-methylureid-p-arsonic acid is a colorless crystalline substance, practically insoluble in cold .water, somewhat soluble on boiling, easily soluble in alkalior alkali carbonate, the neutral solutions being stable. It is precipitated by acids from its solutions and by heavy metal salts, as insoluble salts. It decomposes at 2323 C.

The sodium salt can be obtained as in Example I. It is a stable, colorless crystalline substance which dissolves readily in water and is recommended for use.

E sample II1.ZV-(pkenyZ-p-ars0ni0 (Lo id) oz-p heng lglycin-ureid.

43.4 grams p-aminophenylarsonic acid are dissolved in 200 cc. of normal sodium hydroxid solution and treated with 50 gm. phenyl chloracetyl urea (CJLCHCLCO. NHCONH A0 gm; sodium iodid, and 200 I cc. alcohol. The-mixture is boiled under a reflux for several hours. Un cooling the me ian is obtained. This is urified by redissolving it in dilute alkali car onate or ammonia andthen reprecipitating it with acetic acid. It forms microscopic needles.

The foregoing are a few examples of substances falling within the spirit and scope of our invention. It will be obvious to any one skilled in the art that many variations in the exact constitution of the substances described may be made'wit-hout departing from the spirit and scope of our invention.

What we claim is:

1. As a new product, an aromatic arsonic acid having in its molecule an oz-aminoacylurea side chain, the aromatic nucleus being joined to the oz-amino group in said side chain.

2. As a new product, an aromatic arsonic acid having in its molecule an a-aminoacylurea side chain having the general formula NH.CHR.CONHCONRH, in which R is an alkyl or aryl or hydrogen and R is alkyl, aryl or hydrogen, the aromatic nucleus being joined to the oc-amino group in said side chain.

3. As a new product, an aromatic arsenic acid having in its molecule an cz-aminoacylurea side chain having the general formula NHCH CONHCONHR, in which R is hydrogen or alkyl or aryl.

4. As a new product, an N-phenylglyci'n- B-methylureid-arsonic acid.

5. As a new product N-phenylglycin-fimethylureid-p-arsonic acid.

0 AS OH a I l (H CH CONHCONH.CH

WALTER A. JACOBS, PH. D. WADE ll. BROWN, Ill. D.

MICHAEL HEIDELHERGER, lPH. ll. LOUISE PEARCE, iii. l).

Ali 

